/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2018 wcm.io
    * %%
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * #L%
   */
  package io.wcm.qa.glnm.maven.freemarker.pojo;
  
  import java.lang.reflect.Method;
  import java.lang.reflect.Parameter;
  import java.util.ArrayList;
  
  import org.apache.commons.lang3.StringUtils;
  
  import io.wcm.qa.glnm.maven.freemarker.util.ReflectionUtil;
  
  /**
   * Pojo to generate interaction methods.
   *
   * @since 1.0.0
   */
  public class InteractionMethodPojo {
  
    private static final String CODE_PART_PUBLIC = "public ";
    private static final String CODE_PART_VOID = "void";
    private static final String CODE_PART_RETURN = "return ";
    private Method method;
  
    /**
     * <p>Constructor for InteractionMethodPojo.</p>
     *
     * @param method method to generate delegate for
     */
    public InteractionMethodPojo(Method method) {
      setMethod(method);
    }
  
    /**
     * <p>getBody.</p>
     *
     * @return method body for generated class
     */
    public String getBody() {
      StringBuilder body = new StringBuilder();
      if (!StringUtils.equals(CODE_PART_VOID, method.getReturnType().getCanonicalName())) {
        body.append(CODE_PART_RETURN);
      }
      body.append(getSimpleClassName())
          .append(".")
          .append(getMethodName())
          .append("(")
          .append(getParametersForCall())
          .append(");");
      return body.toString();
    }
  
    private String getMethodName() {
      return getMethod().getName();
    }
  
    private String getSimpleClassName() {
      return getMethod().getDeclaringClass().getSimpleName();
    }
  
    /**
     * <p>getHead.</p>
     *
     * @return method head for generated class
     */
    public String getHead() {
      StringBuilder head = new StringBuilder();
      head.append(CODE_PART_PUBLIC);
      head.append(getHeadForInterface());
      return head.toString();
    }
  
    /**
     * <p>getHeadForInterface.</p>
     *
     * @return method head for generated interface
     */
    public String getHeadForInterface() {
      StringBuilder head = new StringBuilder();
      head.append(getMethodReturnType());
      head.append(" ");
      head.append(getMethodName());
     head.append("(");
     head.append(getParametersForDeclaration());
     head.append(")");
     return head.toString();
   }
 
   private String getMethodReturnType() {
     return method.getGenericReturnType().getTypeName();
   }
 
   /**
    * <p>Getter for the field <code>method</code>.</p>
    *
    * @return a {@link java.lang.reflect.Method} object.
    */
   public Method getMethod() {
     return method;
   }
 
   /**
    * <p>Setter for the field <code>method</code>.</p>
    *
    * @param method2 a {@link java.lang.reflect.Method} object.
    */
   public void setMethod(Method method2) {
     this.method = method2;
   }
 
   private String getParametersForCall() {
     ArrayList<String> paramStrings = new ArrayList<String>();
     for (Parameter parameter : method.getParameters()) {
       if (ReflectionUtil.isSelector(parameter.getType())) {
         paramStrings.add("this");
       }
       else {
         paramStrings.add(parameter.getName());
       }
     }
     return StringUtils.join(paramStrings, ", ");
   }
 
   private String getParametersForDeclaration() {
     ArrayList<String> paramStrings = new ArrayList<String>();
     for (Parameter parameter : method.getParameters()) {
       if (ReflectionUtil.isSelector(parameter.getType())) {
         continue;
       }
       paramStrings.add(getParameterString(parameter));
     }
     return StringUtils.join(paramStrings, ", ");
   }
 
   private String getParameterString(Parameter parameter) {
     StringBuilder paramString = new StringBuilder();
     paramString.append(parameter.getType().getCanonicalName());
     paramString.append(" ");
     paramString.append(parameter.getName());
     return paramString.toString();
   }
 }